Coil and condenser treatment



May15, 1923. 1,455,199

F. J. GROTEN, JR

COIL AND CONDENSER TREATMENT I Filed Feb. 26. 1.926

ea iii say 30 minutes at a Patented lilay v I UNITED-STATES 1,455,199 PATENT" OFFICE.

FRANK J. GBOTEN, JR., or MERIDEN, CO NECTICUT, ASSIGNOR To THE CONNECTICUT TELEPHONE & ELECTRIC 00., 1110., or MERIDEN, CONNECTICUT, A CORPORATION 7 OF CONNECTICUT.

COIL A D CONDENSER TREATMENT.

Application filed February 26, 1920. Serial No. 361,392.

To all whom it may concern:

Be it known that I, FRANK J. GRoTnN, Jr., a citizen of the. United States of America, residing at Meriden, New Haven County, Connecticut, have invented a new and useful Coil and Condenser Treatment, of which the following isa specification.

The main object of my invention is the economical production of compact, durable and eflicient coils and condensers for motor ignition work. The adjustments of the ignition system are of course dependent upon the characteristics of the coil and condenser. It is therefore important that all the devices of a given style shall be uniform in every particular so that the 1 W111 be interchangeable. They must also e capable of quantity production in order to be available for general use. These devices are subjected to varying electrical conditions andto rough usage. As it is practically impossible for the ordinary user or mechanic to inspect or repair such a device,

it should not be'subject to deterioratiom To accomplish the best results at a nummum expense, the 'coils and condensers are first made up according to suitable specifications. The primary coil may consist of one or morelayers of suitably insulated wire such as enameled copper. One layer may be wound on a paper tube or on a core and if there is more than one layer, a sheet.

of insulation such as paper maybe inter-' posed between the layers. The secondary may be made up in the same way usually having a large number of layers of smaller wire. The condenser will usually consist of alternate layers of metal foil an fabric, for instance, two strips of foil .wound with paper between.

The primary, secondary and condenser elements are then heated for say 40 minutes at about C. They are then preferably dried in a vacuum so that the moisture 1s sure to be removed without excessive heating. I have found a temperature of 60 C. and a 'vacuum' of about 29 inches of mercugy for minutes satisfactory. he elements are then suddenly immersed in or flooded'with a special hot thin liquid compound and subjected to ressure until thoroughly impregnated. T is may take ressure of say 25 t 50 lbs. per square inc and a temperature of say to C. I The compound which I have found gives thebest-results consists of approximately 85% by wei ht of a synthetic resin and 15% of oiI. The resin ll prefer to use is known as cumar and consists, I believe, of polymers of paracoumarone, para indene and the polymers of certain other hydrocarbons'obtained from certain coal tar distillates such as crude naphthalene. The polymerization I understand is carried out by the use of sulfuric acid which after the reaction is completed is neutralized with an alkali and the product washed with water and distilled. The melting point depends upon the treatment. This substance has the peculiarit that imlike most gums it can be heated considerably above its melting point without frothing and decomposition. Also it is uniform in quality, free from foreign matter and neither acid or alkali. I prefer to use a product having a melting point of about 80 to 100 C. The oil is preferably pure boiled linseed oil. The mixture must be very liquid well below the charring tem-' perature of the paper or other spacing material employed so as to completely and uni formly impregnate the element without damage to the insulation. The melting point of the mixture is about 60 C. The resin and oil are heated to a temperature of about 130 C. and mixed so as to be very thin and flow readily when hot. I have found that this compound when handled as above indicated ensures a device with exceedingl high and uniform dielectric properties w ich is permanent and reliable in character. The coils and-condenser for a single device are preferably assembledbefore impregnation. This facilitates handling and ensures uniform treatment.

After treatment as above described, the three elements are allowed to drain off excess liquid and then with the usual magnetic core and with a magnetic shield if desired,

are surrounded by a casing and a filler com-. pound is poured into the casing andbetween parts and keep out all moisture. This filler is' preferably composed of the same ingredients as the impregnatin compound only I use a resin having a big or melting point for instance about 130 to C. 84% of this mixed with.16% linseed oil and poured at about C. permanentl fixes the parts in their proper relation an in no manner the elements to more perfectly insulate'the affects the impregnating compound and at the same time has the property of regela tion at the normal working temperature of the coil so that no damage is done if it is cracked. It will so to speak be self-healing. The softening point of the filler is about 82 C.

Fig. 1 shows one form of device ready to be impregnated according to my invention (full size).

Fig. 2 shows the same elements as Fig. 1, but located in acasing and filled.

Fig. 3 is a diagrammatic view of apparatus for impregnating according to my invention.

It will be understood that I have shown but one form of device, and do not consider my invention as limited to any particular form of coil or condenser, or to any particular combination of coils and condenser.

In the particular form shown, 5, 6 and 7 respectively are the primary coil, secondary coil and condenser. The primary coil is shown as wound on a tube 8, a secondary coil on a tube 9 and the condenser has an insulating inner 1a er 10. The core 11 may be of any suitab e type and a magnetic shield 12 may be interposed between the secondary coil and the condenser. The three elements are mounted on a base plate 13 and held together by a rod 14 and cross piece 15. The layer of insulating material 16 is shown interposed between the bottom of the shield,

the core and'the base plate. Another layer of insulation 17 is shown interposed between the primary and secondary coils and. the bottom of the shield 12. As above indicated, the coils and condenser are preferably assembled' and impregnated as aunit. After the elements have been impregnated with the compound as above mentioned, a casing .such as 18 is placed around the condenser and the filler compound 19 poured in as be fore referred to.

The impregnating process may be conveniently carried out 1n apparatus indicated diagrammatically in Fig. 3, where 20 .in-

dicates a vat or tank adapted to hold a number of the units to be impregnated, and 21 indicates a tank for containing the impregnating compound or mixture of resin and oil. hese two tanks may be heated'in any suitable way as for instance by steam jackets. The inner chambers of the tanks are connected by a pipe 22 having avalve 23.

A pump 24 is connected to the inner chamber of tank 20. A condenser may be used between the pump and the tank. In carrying out the process the elements to be treated are placed in the tank 20 and heated for say 40 minutes at a temperature of say 60 C. The pumpis then started and openatedso as to produce a vacuum in the tank 20 of say 29 inches, which is maintained say for an hour and a half. Meanwhile the imsucked over into the tank 20. The valve 23 is then closed and the pump operated until a pressure of say 50 lbs. per square inch is obtained. The coils are left in the impregnating liquid under this pressure for about a half hour and the temperature of the liquid maintained at approximately 130 to 135 C. The valve 23 is then opened and the impregnating liquid which has not been absorbed is forced back into the melting tank 21. The impregnating tank 20 is then opened and the coils allowed to drain for a few minutes. After this, reheating to a temperature above boiling water, say 120 0., will not cause the compound to run out. The coils are then taken out and placed in the casings and filled ith the filler compound. As the impregnating compound has a small co-eflicient of expansion the element can be taken immediately from the impregnating liquid without danger of cracking, and without causing the layers to separate as the article cools.

It should be understood that I have given the details of only one particular product and the particular steps of the preferred process merely as examples and without intending to limit my claims to the exact proportions, times, temperatures, and pressures given. My invention in the broader aspect covers the treatment of coils or condensers alone or combined.

This process of impregnation not only supplements the insulation on the wire and between the la ers of the condenser, but

.seals it uniform y throu hout in case the interfere with the operation of thedevice if it did not actually ruin it.

I claim:

1. The improvement in the art of preparing electrical elements such as coils and condensers which comprises heating the element to approximately 60 C. and then impregnating it with a compound of synthetic resin and oil at a temperature of between and 140 (1., draining the element and then cooling it- 2. The improvement in the artof preparing electrical elements such as coils and condensers which comprises heating the element to approximately 60 C. and then impregnating it with a compound of synthetic resin and oil at a temperature of approxi mately 0., and at a pressure of above 25 lbs. per square inch, draining the element and then cooling it.

3. The improvement in the art of preparing ignition coils which comprises simultaneouslyheatin a plurality of independent completed coils in a receptacle and removing the moisture, flooding the plurality of colls with a hot liquid impregnating compound of synthetic resin and oil, applying pressure to the liquid and coils within the receptacle, draining the receptacle and allowing the coils to dry in thereceptacle.

4. The improvement in'the art of preparing ignition devices which comprises heating a plurality of devices each consisting of coils assembled on a core, submerging the devices in a heated composition containing synthetic resin, applying pressure to force the composition into the interstices of the separate devices, and draining and drying the devices.

5. Improvement in the art of preparing combined ignition coil and condenser devices which comprises heating the coils and condensers after they are assembled, flooding them with a hot liquid composition containing synthetic resin, applying pressure to the composition and the articles submerged therein, draining off the excess liquid and drying the articles.

6. The improvement in the art of prepar- "ing coils, condensers and the like having supports which comprises heating a plurality of the elements while assembled on their supports, submerging the elements and their supports in a hot liquid composition having a melting point of over 50 C. and containing synthetic resin, applying pressure to the liquid composition, and then draining and dryin the elements and their supports. 7. fmprovement in the art of preparing ignition devices which comprises heating them, impregnating the devices with a hot composition containing synthetic resin, placing each device in a suitable casing and lling the casing with a liquid composition containing synthetic resin and having a higher melting point than the impregnating composition and having a softening point at approximately the normal working temperature of the device.

8. The process of preparing an ignition element which comprises heating a plurality of the elements in a closed receptacle to.

drive out moisture contained in the elements, drawing ofi the moisture from the receptacle, flooding the elements with a hot liquid composition containing synthetic resin, applying pressure to the composition and the elements contained therein and maintaining the temperature thereof, draining ofi the excess liquid and drying the elements.

FRANK J. GROTEN, JR. 

